As people's living standard is improved, the people's requirement on display quality is getting higher and higher, and liquid crystal display (LCD) has been very mature, and LCD may be found in cellular phone, camera, computer, television and so on. People's large demands on the display product objectively push the development of display technology, and new display technologies appear continually. Active matrix organic light emitting diode (AMOLED) panel is called as a next generation display technology, and companies such as Samsung Electronics, LG and Philips pay much attention to this new display technology. Currently, Samsung Electronics, LG and Philips take a development of large size AMOLED panel product as the main direction, and Samsung SDI, AU Optronics and so on take medium and small size as the development direction. This is because that AMOLED has better performance than TFT LCD in terms of picture quality, efficiency and cost. However, current AMOLED panel, especially the thin film transistor driving backplane used to drive the panel to display image, its manufacturing process mainly forms desired patterns required by thin film transistor and other devices on various thin film layers therein by patterning process, thus this requires to perform multiple patterning processes, and generally it needs seven or more patterning processes to complete the manufacturing, and the fund required by each patterning process is very expensive. Thus, with respect to the manufacturing of the thin film transistor driving backplane, reducing the times of patterning processes is a difficult problem which restricts its development.